JP7247595B2 - All-solid battery - Google Patents

Description

The present disclosure relates to all-solid-state batteries.

2. Description of the Related Art In recent years, with the rapid spread of information-related equipment and communication equipment such as personal computers, video cameras, and mobile phones, the development of batteries used as power sources for these devices has been emphasized. In addition, in the automobile industry and the like, development of high-output and high-capacity batteries for electric vehicles or hybrid vehicles is underway.
Among all-solid-state batteries, all-solid-state lithium-ion batteries use a battery reaction that involves the movement of lithium ions, so they have a high energy density. It is attracting attention in terms of using a solid electrolyte instead of .

Patent Literature 1 describes that a positive electrode foil made of aluminum foil is covered with a resin.

JP 2014-238915 A

In a stacked all-solid-state battery made by stacking a plurality of battery units, cracks occur inside the electrode layer and solid electrolyte layer when a group of current collector layer protrusions are gathered, and the all-solid-state battery short-circuits. There is a risk of
In view of the above circumstances, an object of the present disclosure is to provide a stacked all-solid-state battery that can suppress the occurrence of short circuits.

In the present disclosure, as a first embodiment, a positive electrode including a positive electrode current collector layer and a positive electrode layer, a negative electrode including a negative electrode current collector layer and a negative electrode layer, and a positive electrode layer disposed between the positive electrode layer and the negative electrode layer An all-solid-state battery comprising a battery laminate obtained by stacking two or more battery units comprising a solid electrolyte layer,
The width of the negative electrode layer is larger than the width of the positive electrode layer,
The negative electrode current collector layer has a negative electrode current collector layer protruding part that protrudes in the surface direction on either side surface of the battery stack,
The positive electrode current collector layer has a positive electrode current collector layer protruding part that protrudes in the surface direction on either side surface of the battery stack,
The battery stack includes a side surface having the negative electrode current collector layer protrusion and a peripheral portion including the side surface of the negative electrode current collector layer protrusion on both side surfaces adjacent to the side surface, or the positive electrode current collector layer protrusion. At least one of the marginal portions including the side surface of the positive electrode current collector layer protruding portion on both side surfaces adjacent to the side surface having the To provide an all-solid-state battery characterized by:

As a second embodiment of the present disclosure, in an all-solid-state battery, at least one of the group of the negative electrode current collector layers and the group of the positive electrode current collector layers is a group of current collector layers, At least one protrusion of the group of protrusions of the group of current collector layers has a current collector layer reinforcing part reinforced with a reinforcing material in at least part of a predetermined region of the protrusion. good too.

As a third embodiment of the present disclosure, in an all-solid-state battery, at least one of the group of the negative electrode current collector layers and the group of the positive electrode current collector layers is a group of current collector layers, Among the group of projections of the group of current collector layers, at least two projections facing each other in the stacking direction of the battery stack contain a resin in at least part of a predetermined region of the projections. An adhesion part may be provided, and at least two of the projections may be adhered via the current collector layer adhesion part so as to be bendable with the region as a starting point.

In the present disclosure, as a fourth embodiment, a positive electrode including a positive electrode current collector layer and a positive electrode layer, a negative electrode including a negative electrode current collector layer and a negative electrode layer, and a positive electrode layer disposed between the positive electrode layer and the negative electrode layer An all-solid-state battery comprising a battery laminate obtained by stacking two or more battery units comprising a solid electrolyte layer,
The width of the negative electrode layer is larger than the width of the positive electrode layer,
The negative electrode current collector layer has a negative electrode current collector layer protruding part that protrudes in the surface direction on either side surface of the battery stack,
The positive electrode current collector layer has a positive electrode current collector layer protruding part that protrudes in the surface direction on either side surface of the battery stack,
At least one of the group of the negative electrode current collector layers and the group of the positive electrode current collector layers, the group of current collector layers, of the group of protrusions of the group of current collector layers, the battery At least two projections facing each other in the stacking direction of the laminate have a current collector layer adhesion portion containing a resin in at least a part of a predetermined region of the projections, and the at least two projections are connected to the current collector. Provided is an all-solid-state battery characterized in that it is adhered so as to be bendable starting from the region via a body layer adhesion portion.

The present disclosure can provide a stacked all-solid-state battery that can suppress the occurrence of short circuits.

It is a cross-sectional schematic diagram which shows an example of the battery unit of this indication. 1 is a cross-sectional schematic diagram showing an example of a first embodiment of an all-solid-state battery of the present disclosure; FIG. FIG. 2 is a schematic plan view showing an example when the all-solid-state battery 100 is viewed from the stacking direction. FIG. 2 is a schematic cross-sectional view showing an example of a second embodiment of an all-solid-state battery of the present disclosure; FIG. 2 is a schematic plan view showing an example when the all-solid-state battery 200 is viewed from the stacking direction. FIG. 4 is a schematic plan view showing another example of the all-solid-state battery 200 viewed from the stacking direction. FIG. 4 is a schematic plan view showing another example of the all-solid-state battery 200 viewed from the stacking direction. FIG. 4 is a schematic cross-sectional view showing an example of a fourth embodiment of an all-solid-state battery of the present disclosure; FIG. 3 is a schematic plan view showing an example of the all-solid-state battery 300 viewed from the stacking direction. FIG. 4 is a schematic plan view showing another example of the all-solid-state battery 300 viewed from the stacking direction.

In the present disclosure, as a first embodiment, a positive electrode including a positive electrode current collector layer and a positive electrode layer, a negative electrode including a negative electrode current collector layer and a negative electrode layer, and a positive electrode layer disposed between the positive electrode layer and the negative electrode layer An all-solid-state battery comprising a battery laminate obtained by stacking two or more battery units comprising a solid electrolyte layer,
The width of the negative electrode layer is larger than the width of the positive electrode layer,
The negative electrode current collector layer has a negative electrode current collector layer protruding part that protrudes in the surface direction on either side surface of the battery stack,
The positive electrode current collector layer has a positive electrode current collector layer protruding part that protrudes in the surface direction on either side surface of the battery stack,
The battery stack includes a side surface having the negative electrode current collector layer protrusion and a peripheral portion including the side surface of the negative electrode current collector layer protrusion on both side surfaces adjacent to the side surface, or the positive electrode current collector layer protrusion. At least one of the marginal portions including the side surface of the positive electrode current collector layer protruding portion on both side surfaces adjacent to the side surface having the To provide an all-solid-state battery characterized by:

In a laminated all-solid-state battery, in order to attach current collector terminals to the positive electrode current collector layer and the negative electrode current collector layer, the terminals are joined to the current collector layer while the current collector layers are bundled together. The tension applied to the current collector layer during convergence may cause cracks in the electrode layer and the solid electrolyte layer near the current collector layer, resulting in a short circuit in the all-solid-state battery.
In addition, even if the battery is not short-circuited at the time of battery manufacture, it is assumed that vibrations or the like during use in a vehicle will transmit a load to the portion near the current collector layer via the terminals, causing the all-solid-state battery to short-circuit.
The present researcher formed a side fixing portion at a predetermined position on the side surface of the battery stack including the current collector layer protrusion, and/or gathered the current collector layer protrusion at a bent portion. By forming the current layer adhesion part, the curving state of the current collector layer protrusion is formed so that the electrode layer and the solid electrolyte layer are not subjected to a load. We have found that it is possible to suppress the occurrence of defects in all-solid-state batteries after they are on the market.

EMBODIMENT OF THE INVENTION Hereinafter, the form for implementing this disclosure is demonstrated in detail, referring drawings.
For convenience of explanation, the same reference numerals are given to the same or corresponding parts in each drawing, and duplicate explanations will be omitted. Not all components of the embodiments are essential, and some components may be omitted. However, the forms shown in the following figures are examples of the present disclosure and do not limit the present disclosure.

FIG. 1 is a cross-sectional schematic diagram showing an example of a battery unit included in an all-solid-state battery of the present disclosure.
As shown in FIG. 1, the battery unit 50 includes a positive electrode 12 including a positive electrode current collector layer 10 and a positive electrode layer 11, a negative electrode 15 including a negative electrode current collector layer 13 and a negative electrode layer 14, a positive electrode layer 11 and a negative electrode layer. It comprises a solid electrolyte layer 16 arranged between 14 .
As shown in FIG. 1 , in the battery unit 50 , the width in the plane direction L of the positive electrode layer 11 is smaller than the width in the plane direction L of the negative electrode layer 14 . This can suppress the generation of dendrites of metal ions such as lithium ions that serve as charge carriers.

[Current collector layer protrusion]
As shown in FIG. 1, the negative electrode current collector layer 13 has a negative electrode current collector layer projecting portion 17 projecting in the surface direction L on the side surface of the battery unit 50, and the positive electrode current collector layer 10 A positive electrode current collector layer projecting portion 18 projecting in the plane direction L is provided on the side surface opposite to the side surface where the negative electrode current collector layer projecting portion 17 of the unit 50 projects. The side surface from which the positive electrode current collector layer protrusion 18 protrudes may be any side surface, and may be the same as the side surface from which the negative electrode current collector layer protrusion 17 protrudes. preferably protrude at positions that do not overlap each other in a plan view so that the current collector layer protruding portions can be easily focused.

(1) First Embodiment FIG. 2 is a cross-sectional schematic diagram showing an example of the first embodiment of the all-solid-state battery of the present disclosure.
As shown in FIG. 2, the all-solid-state battery 100 has a battery stack 60 in which a plurality of battery units 50 indicated by the area surrounded by the dashed line are stacked. The respective battery units 50 share the positive electrode current collector layer 10 or the negative electrode current collector layer 13 of the adjacent battery units 50 . 2, illustration of the positive electrode current collector layer projecting portion 18 is omitted. 2, the description of the battery unit 50 is omitted from the portion indicated by "...". The same applies to "..." shown in FIGS. 4 and 8, which will be described later.
As shown in FIG. 2 , the tip of the negative electrode current collector layer projecting portion 17 is converged by a converging portion 21 .
The number of battery units 50 included in the all-solid-state battery 100 may be at least two, and may be, for example, two or more and fifty or less. The number of battery units 50 included in the all-solid-state battery of another embodiment described later is also the same as that of the all-solid-state battery 100 .

[Side fixed part]
FIG. 3 is a schematic plan view of the all-solid-state battery 100 of FIG. 2 viewed from the stacking direction.
As shown in FIG. 3 , the peripheral portion 30 including the side surface of the negative electrode current collector layer protrusion 17 on both side surfaces adjacent to the side surface having the negative electrode current collector layer protrusion 17 of the all-solid-state battery 100 is made of resin. It has a side fixed part 19 that is A chain line W indicates how the negative electrode current collector layer projecting portion 17 bends (bending starting point) at the time of convergence. The side fixing portion 19 shown in FIG. It is arranged at the position of the edge on the side where the current collector layer protrusion 17 is arranged and at the position near the protrusion base of the side surface of the negative electrode current collector layer protrusion 17, but in the present disclosure, the positive electrode collector The fact that the side fixing part 19 is also arranged at the position of the edge of the side surface of the current collector layer 10 and the positive electrode layer 11 on the side where the negative electrode current collector layer protrusion part 17 is arranged prevents the occurrence of a short circuit in the all-solid-state battery. is preferable from the viewpoint of suppressing The same applies to the side fixing portion 19 shown in FIGS. 5 to 7, which will be described later.
As shown in FIG. 3, from the viewpoint of suppressing the generation of dendrites of metal ions such as lithium ions that serve as charge carriers, the all-solid-state battery 100 has a positive electrode when viewed from the stacking direction. Layer 11 is preferably laminated inside negative electrode layer 14 .
By having the side fixing portion 19, the stress applied to the positive electrode layer 11, the negative electrode layer 14, and the solid electrolyte layer 16 can be reduced to suppress the occurrence of cracks in them, and the occurrence of short circuits in the all-solid-state battery 100 can be suppressed. can do.
In addition, the side fixing portion 19 is a peripheral portion 30 including the side surface of the negative electrode current collector layer protrusion 17 on both side surfaces adjacent to the side surface having the negative electrode current collector layer protrusion 17 of the all-solid-state battery 100, or At least one of the side edges including the side surface of the positive electrode current collector layer protrusion 18 adjacent to the side surface having the positive electrode current collector layer protrusion 18 It is good if there is
In addition, from the viewpoint of further suppressing the occurrence of a short circuit in the all-solid-state battery 100, the negative electrode current collector layer protrusion 17 on both sides adjacent to the side surface having the negative electrode current collector layer protrusion 17 of the all-solid-state battery 100 Side fixation portions 19 are provided on both the marginal portion 30 including the side surface and the marginal portion including the side surface of the positive electrode current collector layer projecting portion 18 on both side surfaces adjacent to the side surface having the positive electrode current collector layer projecting portion 18 . It is preferred to have

Examples of the resin used for the side fixing portion 19 include conventionally known hot-melt agents, thermosetting resins, thermoplastic resins, UV-curable resins, and the like. Although the hardness of the resin is not particularly limited, it is preferably 5 MPa or more.
The side fixing portion 19 may be a thin plate made of the resin, or a hard tape having an adhesive applied to the surface of the resin.
A method of arranging the side fixing portion 19 is not particularly limited, but a method of applying a resin to the side surface and hardening the resin after forming the battery stack 60 can be used. The method of applying the resin is not particularly limited, and various methods such as spraying, doctor blade, and the like can be used.
In addition, the specific position included as the peripheral portion of the battery stack 60 where the side fixing portion 19 is arranged is the side adjacent to the side having the current collector layer protrusion on the stacking side of the battery stack 60, The position of the edge of the side surface of the negative electrode layer 14 on which the current collector layer protrusion is arranged, the position of the edge of the side surface of the solid electrolyte layer 16 on which the current collector layer protrusion is arranged, and the positive electrode It suffices if at least one of the current collector layer protrusion 18 or the negative electrode current collector layer protrusion 17 and the position near the protrusion origin of the side surface of the current collector layer protrusion are included. It is preferable that the positions of the edges of the side surfaces of the positive electrode current collector layer 10 and the positive electrode layer 11 on which the current collector layer protrusions are arranged are included.
In addition, if the side fixing portion 19 is arranged at least in the peripheral portion, the positive electrode current collector layer 10 and the positive electrode layer 11 on both side surfaces of the battery stack 60 adjacent to the side surface having the current collector layer projecting portion are fixed. , the negative electrode current collector layer 13, the negative electrode layer 14, and the solid electrolyte layer 16, but from the viewpoint of improving the energy density of the all-solid-state battery, the side fixing portion 19 is provided only at the peripheral portion. is preferably placed.
The edge portion of the side surface of the battery stack 60 is fixed by the side fixing portion 19, and the position where the current collector layer protrusion is bent when the current collector layer protrusion is converged is the predetermined position of the current collector layer protrusion. And by restraining the current collector layer protrusion so that it does not move, it becomes a structure in which bending stress is not applied to the inside of the electrode layer and the solid electrolyte layer, suppressing the occurrence of short circuits in all-solid-state batteries. can do.

(2) Second Embodiment [Current Collector Layer Reinforcing Part]
FIG. 4 is a cross-sectional schematic diagram showing an example of a second embodiment of the all-solid-state battery of the present disclosure.
In addition to the configuration of the all-solid-state battery 100 shown in FIG. 2, the all-solid-state battery 200 shown in FIG. A current collector layer reinforcing portion 22 reinforced with a reinforcing material is arranged.
As the reinforcing material, the same material as that used for the side fixing portion can be used.
The predetermined region is a region that serves as a bending starting point when the current collector layer protrusions are converged. The position can be adjusted as appropriate so that cracks are less likely to occur.

As a second embodiment of the present disclosure, in the all-solid-state battery 200, at least one of the group of negative electrode current collector layers 13 or the group of positive electrode current collector layers 10 is a group of current collector layers, Of the group of protrusions of the group of current collector layers, at least one protrusion has a current collector layer reinforcing part 22 reinforced with a reinforcing material in at least part of a predetermined region of the protrusion. may be
In addition, at least one protrusion of the group of protrusions of the group of current collector layers has a current collector layer reinforcing part 22 reinforced with a reinforcing material in at least part of a predetermined region of the protrusion. However, from the viewpoint of further suppressing the short circuit of the all-solid-state battery 200, all the projecting portions are reinforced with a reinforcing material in at least a part of a predetermined region of the projecting portion. 22 is preferred.
Furthermore, from the viewpoint of further suppressing short circuits in the all-solid-state battery 200, each protrusion of the group of negative electrode current collector layer protrusions 17 is a group in which at least part of a predetermined region of the protrusion is reinforced with a reinforcing material. A current collector layer having a current collector layer reinforcing portion 22, and in which each protrusion of a group of positive electrode current collector layer protrusions 18 is reinforced with a reinforcing material in at least part of a predetermined region of the protrusion. It is preferable to have a reinforcing portion 22 .

FIG. 5 is a schematic plan view showing an example when the all-solid-state battery 200 is viewed from above in the stacking direction.
The all-solid-state battery 200 only needs to have the current collector layer reinforcing portion 22 reinforced with a reinforcing material in at least a part of the predetermined region of the projecting portion, and as shown in FIG. From the viewpoint of further suppressing the occurrence of a short circuit, along the bending starting point W when converging the current collector layer, both ends and the central part of the area that becomes the bending starting point W so as to have a symmetrical structure from the center line in the plane direction It is preferable to dispose at least the current collector layer reinforcing portion 22 on the .
FIG. 6 is a schematic plan view showing another example when the all-solid-state battery 200 is viewed from above in the stacking direction.
As shown in FIG. 6, from the viewpoint of further suppressing the short circuit of the all-solid-state battery 200, current is collected along the bending starting point W when the current collector layer is converged, in all the regions that become the bending starting points W of the protrusions. It is particularly preferable that the body layer reinforcing portion 22 is arranged.

Since the current collector layer is usually relatively thinner than other layers and has low elasticity, the center of the current collector layer projecting portion is converged in a shape slightly curved inward.
In the case of the first embodiment, the function as a battery is satisfied. It lowers the energy density of the battery.
On the other hand, in the case of the second embodiment, in addition to the side fixing portion 19 of the first embodiment, a current collector layer reinforcing portion 22 is provided at a predetermined position of the current collector layer protruding portion, thereby The amount of bending of the current collector layer protruding portion can be reduced, and the occurrence of short circuits in the all-solid-state battery can be further suppressed. In addition, the usage amount of the side fixing portion 19 can be reduced, and the energy density of the all-solid-state battery can be improved.

(3) Third Embodiment [Collector Layer Adhesion Portion]
A third embodiment of the all-solid-state battery of the present disclosure will be described with reference to FIG.
FIG. 7 is a schematic plan view showing another example when the all-solid-state battery 200 is viewed from above in the stacking direction. FIG. 7 is a diagram showing an example of a case where a current collector layer bonding portion 23 is provided instead of the current collector layer reinforcing portion 22. As shown in FIG. The current collector layer bonding portion 23 will be described later.
The current collector layer adhesion portion 23 controls the position where the current collector layer bends during focusing so that it becomes the current collector layer protrusion, and the side fixing portion 19 prevents the current collector layer protrusion from moving. By restraining them, a structure in which bending stress is less likely to be applied to the inside of the positive electrode layer 11, the negative electrode layer 14, and the solid electrolyte layer 16 can be obtained, and the reliability of the insulation assurance of the all-solid-state battery can be ensured. In the all-solid-state battery 200 shown in FIG. 7, the current collector layers are fixed to each other by the current collector layer adhesion portion 23 provided in a predetermined region of the current collector layer protrusion portion, so that the current collector layer serves as a bending starting point W. It is a focused structure.
In the third embodiment, in addition to the side fixing portion 19 of the first embodiment, a current collector layer bonding portion 23 is provided at a predetermined position of the current collector layer protruding portion so that the current collector at the time of focusing is It is possible to reduce the amount of bending of the layer projecting portion, and further suppress the occurrence of short circuits in the all-solid-state battery. In addition, the usage amount of the side fixing portion 19 can be reduced, and the energy density of the all-solid-state battery can be improved.

(4) Fourth Embodiment FIG. 8 is a schematic cross-sectional view showing an example of a fourth embodiment of the all-solid-state battery of the present disclosure.
The all-solid-state battery 300 shown in FIG. 8 is the same as the all-solid-state battery 100 shown in FIG. Note that FIG. 8 shows the battery in a state before the negative electrode current collector layer protruding portion 17 is converged. Further, in FIG. 8, the portion surrounded by the solid line indicates the region that becomes the starting point of bending of the current collector layer projecting portion.
As a fourth embodiment of the present disclosure, in the all-solid-state battery 300, at least one of the group of the negative electrode current collector layers 13 and the group of the positive electrode current collector layers 10 is a group of current collector layers. Among the group of protrusions of the group of current collector layers, at least two protrusions facing each other in the stacking direction of the battery stack 60 contain a resin in at least part of a predetermined region of the protrusions. It suffices that it has a collector layer adhesion portion, and at least two of the projecting portions are adhered via the collector layer adhesion portion so as to be bendable with the region as a starting point.
In the all-solid-state battery 300 of the present disclosure, at least two protruding portions may be bonded via the current collector layer bonding portion so as to be bendable starting from a predetermined region. When there are five, at least two negative electrode current collector layer protrusions 17 need only be bonded via the current collector layer bonding part 23, and only one in the middle in the stacking direction is not bonded, and the remaining The four negative electrode current collector layer protrusions 17 may be adhered to each other between the two negative electrode current collector layer protrusions 17 facing each other, and all the five negative electrode current collector layer protrusions 17 may be bonded to each other. It may be glued.
In the fourth embodiment, by providing a current collector layer bonding portion 23 at a predetermined position of the current collector layer protrusion, the amount of bending of the current collector layer protrusion during focusing is reduced. The first The energy density of the all-solid-state battery can be improved compared to the embodiments of 1 to 3.

FIG. 9 is a schematic plan view showing an example when the all-solid-state battery 300 is viewed from above in the stacking direction.
The all-solid-state battery 300 only needs to have the current collector layer adhesion part 23 containing a resin in at least part of the predetermined region of the current collector layer protrusion.
The current collector layer bonding portion 23 may be provided on the side surface of the current collector layer protrusion as long as it is disposed in at least a part of the region where the current collector layer protrusion starts bending when converging. .
As shown in FIG. 9, from the viewpoint of further suppressing the occurrence of short circuits in the all-solid-state battery, along the bending starting point W when the current collector layers are converged, the structure is symmetrical from the center line in the planar direction. It is preferable to dispose at least the current collector layer bonding portions 23 at both ends and the central portion of the region that serves as the bending starting point W on one side surface of the current collector layer projecting portion.
FIG. 10 is a schematic plan view showing another example when the all-solid-state battery 300 is viewed from above in the stacking direction.
As shown in FIG. 10, from the viewpoint of further suppressing the short circuit of the all-solid-state battery 300, the bending starting point W of at least one side surface of the current collector layer protruding portion along the bending starting point W when the current collector layer is converged It is particularly preferable that the current collector layer bonding portion 23 is arranged in all of the regions where

As the adhesive used for the current collector layer adhesion portion 23, conventionally known adhesives and pressure-sensitive adhesives can be used, and the resin used for the side fixing portion can also be used.

The method of arranging the current collector layer adhesive portion 23 is not particularly limited, but from the viewpoint of improving work efficiency, one sheet at a time is attached to the current collector layer protrusions using a dispenser or the like before the current collector layer protrusions are converged. agent may be applied. Alternatively, a tape or the like having an adhesive applied to the surface thereof may be adhered to a predetermined region of the current collector layer projecting portion. The current collector layer adhesion part 23 may be arranged after the battery laminate 60 is produced, or may be arranged in advance in a predetermined region of the current collector layer projecting part before the battery laminate 60 is produced. .

[Positive electrode]
The positive electrode has a positive electrode layer and a positive electrode collector layer.

[Positive electrode layer]
The positive electrode layer contains a positive electrode active material, and may contain a solid electrolyte, a conductive material, a binder, and the like as optional components.

As the positive electrode active material, for example, Li _x M _y O _z (M is a transition metal element, x = 0.02 to 2.2, y = 1 to 2, z = 1.4 to 4). can be mentioned. In the above general formula, M includes at least one selected from the group consisting of Co, Mn, Ni, V, Fe and Si, and may be at least one selected from the group consisting of Co, Ni and Mn. . Specific examples of such positive electrode active materials include LiCoO ₂ , LiMnO ₂ , LiNiO ₂ , LiVO ₂ , LiNi _1/3 Co _1/3 Mn _1/3 O ₂ , LiMn ₂ O ₄ , Li(Ni _{0 .5Mn1.5} ) _O4 , _Li2FeSiO4 , _{Li2MnSiO4 and} the _{like .
Examples of} positive electrode active materials other than _LixMyOz represented by the general formula include lithium titanate ( _e.g. , _Li4Ti5O12 ), lithium metal phosphate ( _{LiFePO4 , LiMnPO4} , _LiCoPO4 , _LiNiPO4 ), transition metal oxides ( _V2O5 , _MoO3 ), _TiS2 , LiCoN _, Si _{, SiO2 , Li2SiO3} , _Li4SiO4 , and lithium storage intermetallic compounds (e.g. _Mg2Sn , _Mg2Ge , Mg ₂ Sb, Cu ₃ Sb) and the like.
Although the shape of the positive electrode active material is not particularly limited, it may be particulate.
A coat layer containing a Li ion conductive oxide may be formed on the surface of the positive electrode active material. This is because the reaction between the positive electrode active material and the solid electrolyte can be suppressed.
Li ion conductive oxides include, for example, LiNbO ₃ , Li ₄ Ti ₅ O ₁₂ , Li ₃ PO ₄ and the like.
The content of the positive electrode active material in the positive electrode layer is not particularly limited, but may be, for example, within the range of 10% by mass to 100% by mass.
Examples of the solid electrolyte used for the positive electrode layer include those similar to the solid electrolyte used for the solid electrolyte layer described later. The content ratio of the solid electrolyte in the positive electrode layer is not particularly limited.

As the conductive material, a known material can be used, and examples thereof include carbon materials, metal particles, and the like. Examples of the carbon material include at least one selected from the group consisting of carbon black such as acetylene black and furnace black, carbon nanotubes, and carbon nanofibers. and at least one selected from the group consisting of carbon nanofibers. The carbon nanotube and carbon nanofiber may be VGCF (vapor grown carbon fiber). Metal particles include particles of Al, Ni, Cu, Fe, SUS, and the like.
The content of the conductive material in the positive electrode layer is not particularly limited.

Examples of binders include rubber binders such as butadiene rubber, hydrogenated butadiene rubber, styrene butadiene rubber (SBR), hydrogenated styrene butadiene rubber, nitrile butadiene rubber, hydrogenated nitrile butadiene rubber, and ethylene propylene rubber, polyvinylidene fluoride ( PVdF), polyvinylidene fluoride-polyhexafluoropropylene copolymer (PVDF-HFP), polytetrafluoroethylene, and fluoride-based binders such as fluororubber, polyolefin-based thermoplastic resins such as polyethylene, polypropylene, and polystyrene, imide resins such as polyimide and polyamideimide; amide resins such as polyamide; acrylic resins such as polymethyl acrylate and polyethyl acrylate; and methacrylic resins such as polymethyl methacrylate and polyethyl methacrylate. . The content of the binder in the positive electrode layer is not particularly limited.

For the positive electrode layer, for example, a positive electrode layer slurry is prepared by putting a positive electrode active material and, if necessary, a conductive material, a binder, etc. into a solvent and stirring the slurry, and the slurry is applied on one surface of the support. It is obtained by drying with
Solvents include, for example, butyl acetate, butyl butyrate, heptane, N-methyl-2-pyrrolidone, and the like.
The method for applying the positive electrode layer slurry onto one surface of the support is not particularly limited, and includes a doctor blade method, a metal mask printing method, an electrostatic coating method, a dip coating method, a spray coating method, a roll coating method, and a gravure coating method. , and screen printing methods.
As another method of forming the positive electrode layer, the positive electrode layer may be formed by pressure-molding a powder of a positive electrode mixture containing the positive electrode active material and, if necessary, other components.

[Positive collector layer]
The positive electrode current collector layer has a positive electrode current collector layer protruding part that protrudes in the surface direction. Further, a positive electrode current collector tab may be electrically connected to the positive electrode current collector layer protruding portion.
The positive electrode current collector layer has a function of collecting current of the positive electrode layer, and can be used by appropriately selecting a known one that can be used as a positive electrode current collector for an all-solid-state battery, and is not particularly limited. .
Examples of materials for the positive electrode current collector layer include metal materials such as SUS, Ni, Cr, Au, Pt, Al, Fe, Ti, and Zn.
The form of the positive electrode current collector layer is not particularly limited, and may be in various forms such as foil-like and mesh-like. The thickness and width of the projecting portion of the positive electrode current collector layer and the other portion may be the same or different, and can be appropriately set according to the size of the all-solid-state battery. Also, the length of the positive electrode current collector layer protrusion is not particularly limited, but may be appropriately adjusted to a length that facilitates convergence.

[Coating layer]
The positive electrode current collector layer may have a coat layer containing a conductive material such as Ni, Cr, or C (carbon) on at least part of the surface of a metal foil containing metal. By having the coat layer, it is possible to suppress an increase in internal resistance due to the formation of a passive film on the surface of the positive electrode current collector layer.
The coat layer contains at least a conductive material, and if necessary, may further contain other components such as a binder. Examples of the binder that the coat layer may contain include the same binders that the positive electrode layer may contain. Also, the coat layer may be a plated layer or a deposited layer made of a conductive material.
As a specific example of the coating layer, for example, it contains 15% by mass of C (carbon) as a conductive material, further contains 85% by mass of polyvinylidene fluoride (PVDF) as a binder, and has a volume resistivity of 10×10 ^{3 .} A carbon coat layer of Ωcm can be mentioned.
Although the thickness of the coat layer is not particularly limited, it is preferably 1 μm or more and 50 μm or less, for example, about 10 μm, from the viewpoint of suppressing an increase in internal resistance.
On the surface of the positive electrode current collector layer, the coat layer is arranged in a region where the positive electrode current collector layer and the positive electrode layer that are adhered to each other overlap, which makes it easy to suppress an increase in the internal resistance of the all-solid-state battery. preferred from

[Negative electrode]
The negative electrode has a negative electrode layer and a negative electrode collector layer.

[Negative electrode layer]
The negative electrode layer contains a negative electrode active material, and may contain a solid electrolyte, a conductive material, a binder, and the like as optional components.

Conventionally known materials can be used as the negative electrode active material, and examples thereof include Li simple substance, lithium alloys, carbon, Si simple substances, Si alloys, and Li ₄ Ti ₅ O ₁₂ (LTO).
Lithium alloys include LiSn, LiSi, LiAl, LiGe, LiSb, LiP, and LiIn.
Examples of Si alloys include alloys with metals such as Li, and may be alloys with at least one metal selected from the group consisting of Sn, Ge, and Al.
The shape of the negative electrode active material is not particularly limited, but may be, for example, particulate or thin film.
When the negative electrode active material is particles, the average particle diameter (D50) of the particles is, for example, preferably 1 nm or more and 100 μm or less, more preferably 10 nm or more and 30 μm or less.

Examples of the conductive material, binder, and solid electrolyte contained in the negative electrode layer are the same as those contained in the positive electrode layer described above.

The method for forming the negative electrode layer is not particularly limited, but there is a method of pressure-molding a negative electrode mixture powder containing negative electrode active material and, if necessary, other components such as a conductive material and a binder. Further, as another example of the method for forming the negative electrode layer, a negative electrode layer slurry containing a negative electrode active material, a solvent, and optionally other components such as a conductive material and a binder is prepared, and the negative electrode layer slurry is supported. A method of applying the negative electrode layer slurry onto one surface of the body and drying the negative electrode layer slurry may be used. Examples of the solvent used for the negative electrode layer slurry include the same solvents as those used for the positive electrode layer slurry. The method of applying the negative electrode slurry onto one surface of the support includes the same method as the method of applying the positive electrode slurry.

[Negative electrode current collector layer]
The negative electrode current collector layer has a negative electrode current collector layer protruding part that protrudes in the surface direction. Further, a negative electrode collector tab may be electrically connected to the negative electrode collector layer projecting portion.
The negative electrode current collector layer has a function of collecting current for the negative electrode layer, and can be used by appropriately selecting a known one that can be used as a negative electrode current collector for an all-solid-state battery, and is not particularly limited.
Examples of materials for the negative electrode current collector layer include metal materials such as SUS, Cu, Ni, Fe, Ti, Co, and Zn.
The form of the negative electrode current collector layer is not particularly limited, and may be the same form as the positive electrode current collector layer. The thickness and width of the projecting portion of the negative electrode current collector layer and the other portion may be the same or different, and can be appropriately set according to the size of the all-solid-state battery. In addition, the length of the negative electrode current collector layer protrusion is not particularly limited, but may be appropriately adjusted to a length that facilitates convergence.

[Solid electrolyte layer]
The solid electrolyte layer contains at least a solid electrolyte.
Solid electrolytes include sulfide-based solid electrolytes, oxide-based solid electrolytes, and the like.
Examples of sulfide solid electrolytes include Li ₂ SP ₂ S ₅ , Li ₂ S—SiS ₂ , LiX—Li ₂ S—SiS ₂ , LiX—Li ₂ SP ₂ S ₅ , LiX—Li ₂ O—Li ₂ SP ₂ S ₅ , LiX—Li ₂ SP ₂ O ₅ , LiX—Li ₃ PO ₄ —P ₂ S ₅ , Li ₃ PS ₄ and the like. The above description of "Li ₂ SP ₂ S ₅ " means a material obtained by using a raw material composition containing Li ₂ S and P ₂ S ₅ , and the same applies to other descriptions. "X" in LiX above represents a halogen element. One or more kinds of LiX may be contained in the raw material composition containing LiX. When two or more types of LiX are included, the mixing ratio of the two or more types is not particularly limited.
As the sulfide-based solid electrolyte, for example, Li ₂ S and P ₂ S _{5 are added so that the mass ratio of Li 2 S and P 2 S 5 (} Li ₂ S/P ₂ S ₅ ) is _0.5 or more _. and a sulfide-based solid electrolyte prepared by mixing. In addition, a sulfide-based solid electrolyte prepared by mixing Li ₂ S and P ₂ S ₅ so that the mass ratio of Li ₂ S:P ₂ S ₅ is 70:30 has good ion conductivity. It is preferably used from the point.
The molar ratio of each element in the sulfide-based solid electrolyte can be controlled by adjusting the content of each element in the raw material. Also, the molar ratio and composition of each element in the sulfide-based solid electrolyte can be measured, for example, by ICP emission spectrometry.

The sulfide-based solid electrolyte may be glass, crystal, or crystalline glass-ceramics.
The crystalline state of the sulfide-based solid electrolyte can be confirmed, for example, by subjecting the sulfide-based solid electrolyte to powder X-ray diffraction measurement using CuKα rays.

Glass can be obtained by subjecting a raw material composition (for example, a mixture of Li ₂ S and P ₂ S ₅ ) to amorphous processing. Examples of amorphous processing include mechanical milling. The mechanical milling may be dry mechanical milling or wet mechanical milling, but the latter is preferred. This is because the raw material composition can be prevented from sticking to the walls of the container or the like.
Mechanical milling is not particularly limited as long as it is a method of mixing the raw material composition while applying mechanical energy. Among them, a ball mill is preferable, and a planetary ball mill is particularly preferable. This is because the desired glass can be efficiently obtained.

Glass-ceramics can be obtained, for example, by heat-treating glass.
Also, crystals can be obtained, for example, by heat-treating glass, or subjecting a raw material composition to solid-phase reaction treatment.
The heat treatment temperature may be any temperature higher than the crystallization temperature (Tc) observed by thermal analysis measurement of glass, and is usually 195° C. or higher. On the other hand, the upper limit of the heat treatment temperature is not particularly limited.
The crystallization temperature (Tc) of glass can be measured by differential thermal analysis (DTA).
The heat treatment time is not particularly limited as long as the desired degree of crystallinity is obtained. .
The method of heat treatment is not particularly limited, but for example, a method using a kiln can be mentioned.

Examples of oxide solid electrolytes include Li _6.25 La ₃ Zr ₂ Al _0.25 O ₁₂ , Li ₃ PO ₄ and Li _3+x PO _4-x N _x (LiPON).

The shape of the solid electrolyte is preferably particulate from the viewpoint of ease of handling.
The average particle diameter (D50) of the particles of the solid electrolyte is not particularly limited, but the lower limit is preferably 0.5 μm or more, and the upper limit is preferably 2 μm or less.
Solid electrolytes can be used singly or in combination of two or more. Moreover, when using 2 or more types of solid electrolytes, you may mix 2 or more types of solid electrolytes.

In the present disclosure, unless otherwise specified, the average particle diameter of particles is the volume-based median diameter (D50) measured by laser diffraction/scattering particle size distribution measurement. In the present disclosure, the median diameter (D50) is the diameter (volume average diameter) at which the cumulative volume of particles is half (50%) of the total volume when the particles are arranged in order from the smallest particle size.

The content ratio of the solid electrolyte in the solid electrolyte layer is not particularly limited.

The solid electrolyte layer may contain a binder that binds the solid electrolytes together from the viewpoint of exhibiting plasticity. As such a binder, the binder etc. which can be contained in the positive electrode layer mentioned above can be illustrated. However, in order to make it easier to increase the output of the battery, from the viewpoint of preventing excessive aggregation of the solid electrolyte and making it possible to form a solid electrolyte layer having a uniformly dispersed solid electrolyte, the solid electrolyte layer The content of the binder to be contained is preferably 5.0% by mass or less.

The thickness of the solid electrolyte layer is appropriately adjusted depending on the configuration of the battery and is not particularly limited, and is usually 0.1 μm or more and 1 mm or less.
The solid electrolyte layer may be formed by, for example, pressing powder of the solid electrolyte layer material containing the solid electrolyte and, if necessary, other components.

The all-solid-state battery optionally includes a positive electrode, a negative electrode, and an outer casing housing a solid electrolyte layer.
The shape of the exterior body is not particularly limited, but a laminate type or the like can be mentioned.
The material of the exterior body is not particularly limited as long as it is stable in the electrolyte, and examples thereof include polypropylene, polyethylene, resins such as acrylic resins, and embossed aluminum laminates.

All-solid-state batteries include all-solid-state lithium batteries that use the deposition-dissolution reaction of metallic lithium as the negative electrode reaction, all-solid-state lithium-ion batteries that use intercalation of lithium into the negative electrode active material as the negative electrode reaction, and all-solid-state batteries. Examples include a sodium battery, an all-solid magnesium battery, an all-solid calcium battery, and the like, and an all-solid lithium ion battery may also be used. Moreover, the all-solid-state battery may be a primary battery or a secondary battery.
Examples of the shape of the all-solid-state battery include coin type, laminate type, cylindrical type, rectangular type, and the like.

[Method for manufacturing all-solid-state battery]
The method for manufacturing the all-solid-state battery of the present disclosure is not particularly limited as long as it is a method capable of obtaining the all-solid-state battery of the present disclosure described above, and can be manufactured, for example, by the following method.
First, a sheet-like solid electrolyte layer is arranged between a sheet-like positive electrode and a sheet-like negative electrode to form a battery unit. Then, a plurality of battery units are stacked to form a battery stack.
In the case of the first embodiment, after that, the battery stack is sandwiched between two flat plates from above and below in the stacking direction of the battery stack, and a surface pressure (preferably 0.05 to 2 MPa) is applied to the battery stack. A predetermined position on the side surface of the battery stack is filled with a resin, the resin is cured, and the side fixing portion is arranged at a predetermined position on the side surface of the battery stack.
In the case of the second embodiment or the third embodiment, after the battery stack is formed, a dispenser, a tape sticking device, or the like is applied to a predetermined region of the current collector layer projecting portion before arranging the side fixing portion. is used to form a current collector layer reinforcing portion or a current collector layer adhesion portion.
In the case of the fourth embodiment, after the battery laminate is produced, the current collector layer is adhered to a predetermined region of the current collector layer protrusion using a dispenser or a tape sticking device without arranging the side fixing portion. form a part.
After forming the side fixing portion or forming the current collector layer adhesion portion, the positive electrode current collector layer projecting portion and the negative electrode current collector layer projecting portion are respectively bundled. A current collecting lead or the like is used to connect the positive electrode current collector layer projecting portion and the positive electrode terminal to the positive electrode terminal leading to the outside, and a current collecting lead or the like is used to connect to the negative electrode terminal. An all-solid battery may be formed by connecting the negative electrode current collector layer projecting portion and the negative electrode terminal.
Embossed aluminum laminate that can enclose the all-solid-state battery is prepared on the top and bottom of the all-solid-state battery in the stacking direction. It may be sealed. It does not matter whether the inside of the exterior body is depressurized or not, and it may be adjusted as appropriate during design.

The pressure applied to the all-solid-state battery when the all-solid-state battery of the present disclosure is used can be, for example, 1 MPa or more and 45 MPa or less, and the pressure applied to the all-solid-state battery when the all-solid-state battery is not in use is For example, it can be 0 MPa or more and 1 MPa or less.

Methods for pressurizing an all-solid-state battery include, for example, mechanical pressurization and gas pressurization.
Examples of mechanical pressurization include a method of driving a motor to apply pressure in the stacking direction of the all-solid-state battery via a ball screw, and a method of driving a motor to apply pressure in the stacking direction of the all-solid-state battery via hydraulic pressure. mentioned. In the mechanical pressurization, after pressurizing or depressurizing the all-solid-state battery to a predetermined pressure, by fixing the moving part of the machine with a mechanical stopper, the energy consumption associated with driving the motor can be minimized.
Gas pressurization includes, for example, a method of pressurizing the all-solid-state battery via a pressurized gas from a pre-mounted gas cylinder.

The all-solid-state battery of the present disclosure is used, for example, as a power source mounted on a vehicle or a power source for driving portable electronic devices, etc., but is not limited to these uses.
Vehicles to which the all-solid-state battery of the present disclosure is applied are not limited to electric vehicles that are equipped with a battery and no engine, and include hybrid vehicles that are equipped with both a battery and an engine.

10 Positive electrode current collector layer 11 Positive electrode layer 12 Positive electrode 13 Negative electrode current collector layer 14 Negative electrode layer 15 Negative electrode 16 Solid electrolyte layer 17 Negative electrode current collector layer protrusion 18 Positive electrode current collector layer protrusion 19 Side fixing part 21 Converging part 22 Current collector layer reinforcing portion 23 Current collector layer bonding portion 30 Edge portion 50 Battery unit 60 Battery laminate 100 All-solid battery 200 All-solid battery 300 All-solid battery L Planar direction W Bending starting point of current collector layer protrusion

Claims (7)

2 a battery unit comprising a positive electrode including a positive electrode current collector layer and a positive electrode layer, a negative electrode including a negative electrode current collector layer and a negative electrode layer, and a solid electrolyte layer disposed between the positive electrode layer and the negative electrode layer An all-solid-state battery comprising a battery stack formed by stacking one or more,
The width of the negative electrode layer is larger than the width of the positive electrode layer,
The negative electrode current collector layer has a negative electrode current collector layer protruding part that protrudes in the surface direction on either side surface of the battery stack,
The positive electrode current collector layer has a positive electrode current collector layer protruding part that protrudes in the surface direction on either side surface of the battery stack,
The battery stack includes a side surface having the negative electrode current collector layer protrusion and a peripheral portion including the side surface of the negative electrode current collector layer protrusion on both side surfaces adjacent to the side surface, or the positive electrode current collector layer protrusion. a side fixing portion made of a resin on at least one of the marginal portions including the side surface of the positive electrode current collector layer protruding portion on both side surfaces adjacent to the side surface having the side surface fixing portion,
When the side fixing portion is provided in a peripheral portion including the side surface of the negative electrode current collector layer projecting portion on both side surfaces adjacent to the side surface having the negative electrode current collector layer projecting portion, the negative electrode the position of the edge of the side surface of the layer on which the negative electrode current collector layer protrusion is arranged, the position of the edge of the side surface of the solid electrolyte layer on which the negative electrode current collector layer protrusion is arranged, and arranged at a position near the protruding base of the side surface of the negative electrode current collector layer protruding portion,
When the side fixing portion is provided in a peripheral portion including the side surface of the positive electrode current collector layer projecting portion on both side surfaces adjacent to the side surface having the positive electrode current collector layer projecting portion, the peripheral portion includes the positive electrode the position of the edge of the side surface of the layer on which the positive electrode current collector layer protrusion is arranged, the position of the edge of the side surface of the solid electrolyte layer on which the positive electrode current collector layer protrusion is arranged, and arranged at a position near the protruding base of the side surface of the positive electrode current collector layer protruding portion ,
At least one of the group of the negative electrode current collector layers and the group of the positive electrode current collector layers includes at least one of the group of projecting portions of the group of current collector layers. 1. An all-solid-state battery, wherein each projection has a current-collector-layer reinforcing portion reinforced with a reinforcing material in at least a part of a predetermined region of the projection. At least one of the group of the negative electrode current collector layers and the group of the positive electrode current collector layers, the group of current collector layers, of the group of protrusions of the group of current collector layers, the battery At least two projections facing each other in the stacking direction of the laminate have a current collector layer adhesion portion containing a resin in at least a part of a predetermined region of the projections, and the at least two projections are connected to the current collector. 2. The all-solid-state battery according to claim 1, wherein said solid-state battery is adhered so as to be bendable starting from said region via said body layer adhesion portion. 2 a battery unit comprising a positive electrode including a positive electrode current collector layer and a positive electrode layer, a negative electrode including a negative electrode current collector layer and a negative electrode layer, and a solid electrolyte layer disposed between the positive electrode layer and the negative electrode layer An all-solid-state battery comprising a battery stack formed by stacking one or more,
The width of the negative electrode layer is larger than the width of the positive electrode layer,
The negative electrode current collector layer has a negative electrode current collector layer protruding part that protrudes in the surface direction on either side surface of the battery stack,
The positive electrode current collector layer has a positive electrode current collector layer protruding part that protrudes in the surface direction on either side surface of the battery stack,
At least one of the group of the negative electrode current collector layers and the group of the positive electrode current collector layers, the group of current collector layers, of the group of protrusions of the group of current collector layers, the battery At least two projections facing each other in the stacking direction of the laminate have a current collector layer adhesion portion containing a resin in at least a part of a predetermined region of the projections, and the at least two projections are connected to the current collector. An all-solid-state battery, characterized in that the solid-state battery is adhered so as to be bendable with the region as a starting point via a body layer adhesion portion. When the side fixing portion is provided in a peripheral portion including the side surface of the negative electrode current collector layer projecting portion on both side surfaces adjacent to the side surface having the negative electrode current collector layer projecting portion, the peripheral portion further includes: arranged at the position of the edge of the side surface of the positive electrode current collector layer and the positive electrode layer on the side where the negative electrode current collector layer protrusion is arranged;
When the side fixing portion is provided in a peripheral portion including the side surface of the positive electrode current collector layer protrusion on both side surfaces adjacent to the side surface having the positive electrode current collector layer protrusion, the peripheral portion further includes: 2. The all-solid-state battery according to claim 1, wherein said negative electrode current collector layer and said negative electrode current collector layer are arranged at a position of an edge of a side surface of said negative electrode layer on a side where said positive electrode current collector layer protrusion is arranged. The current collector layer reinforcing portion is a region that serves as the bending starting point W of the projecting portion along the bending starting point W at the time of convergence of the current collector layer so as to have a symmetrical structure from the center line in the plane direction. 2. The all-solid-state battery according to claim 1 , arranged at least at both ends and the center of the. 2. The overall structure according to claim 1 , wherein the current collector layer reinforcing portion is arranged along the bending starting point W when the current collector layer is converged, in all of the regions serving as the bending starting points W of the protrusions. solid state battery. The all-solid-state battery according to any one of claims 1 to 6 , wherein the solid electrolyte layer includes a sulfide-based solid electrolyte or an oxide-based solid electrolyte.

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